Three-dimensional (3D) sandwich composites are an excellent material, boasting light weight, high strength, and high specific stiffness. For materials comprising this structure, a new type of sandwich composite, made with a 3D fabric reinforcement structure, was independently developed. A sandwich composite is a lightweight composite with practical mechanical properties, manufactured using compression moulding techniques. The 3D fabrics were produced by sewing jute yarns having configurable structures using Kevlar fibre threads, while an epoxy resin was impregnated into the 3D fabrics, achieving a more uniform resin and voids distribution and thus a better polyurethane resin impregnation for the sandwich composite. Jute composite panels were used to form the upper and lower skins during the compression moulding process. The composites had been subjected to compression, flexural and impact tests, and their fracture surfaces had been characterised by scanning electron microscopy (SEM). Mechanical tests showed that the compression and flexural strengths of the composites markedly increased, reaching 21.4 and 18.5 MPa respectively, which was approximately 7.7 and 3.8 times higher than similar properties of the blank composites without 3D fabrics. SEM micrographs of the composites showed the presence of jute fibre pull-outs in the 3D fabrics and the existence of voids in the composite.

三维（3D）三明治复合材料是一种出色的材料，具有重量轻，强度高和比刚度高的特点。对于包含这种结构的材料，采用3D织物增强结构制成的新型三明治复合材料是独立开发的。夹心复合材料是使用压缩成型技术制造的具有实用机械性能的轻质复合材料。通过使用凯夫拉尔纤维线缝制具有可配置结构的黄麻纱来生产3D织物，同时将环氧树脂浸渍到3D织物中，从而实现了更均匀的树脂和空隙分布，从而为三明治复合材料实现了更好的聚氨酯树脂浸渍。黄麻复合板在压缩成型过程中用于形成上下蒙皮。对复合材料进行了压缩，弯曲和冲击测试，并通过扫描电子显微镜（SEM）对它们的断裂表面进行了表征。力学测试表明，复合材料的抗压强度和弯曲强度显着提高，分别达到21.4 MPa和18.5 MPa，比没有3D织物的空白复合材料的相似性能高大约7.7和3.8倍。复合材料的SEM显微照片显示3D织物中存在黄麻纤维拉出物，并且复合材料中存在空隙。这比没有3D织物的空白复合材料的相似性能分别高7.7和3.8倍。复合材料的SEM显微照片显示3D织物中存在黄麻纤维拉出物，并且复合材料中存在空隙。这比没有3D织物的空白复合材料的相似性能分别高7.7和3.8倍。复合材料的SEM显微照片显示3D织物中存在黄麻纤维拉出物，并且复合材料中存在空隙。